Fig. 7 .

Aquaporins (AQPs) are proteins with a molecular weight of 26–30 kDa and are composed of ∼250–290 amino acid residues. AQPs pass through the membrane six times in the vicinity of the pore (membrane-spanning) and allow water to travel in both directions through this pore. Reprinted with permission from Reference³⁰⁹⁾ Figure 1 . (Zelenina M: Regulation of brain aquaporins. Neurochem Int 57: 468–488, 2010).